Footwear differs in type and style including dress shoes, casual shoes, athletic shoes, work shoes, boots, dance shoes, and the like. Although there are standards for footwear sizing, footwear is produced by a wide array of domestic and international manufacturers creating substantial inconsistencies in the sizing between similar footwear styles. Materials used in the construction of footwear also provide varying degrees of stretching and size shifting throughout the life of the footwear.
In addition to the production and wear variances in footwear, the wearer of footwear creates many additional sizing challenges. Such challenges include the typical uniqueness and size variation between a wearer's left and right foot, changes in body weight, disease or injury, and the wearers' walking/running habits. The growth of the children, infant's, and teen's feet requires sizing changes at a higher frequency than that of an adult.
What is needed is a shoe insert that adjusts the size of footwear to match the size of the wearer's foot.